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1.
Supporting mobile database access through query by icons   总被引:2,自引:0,他引:2  
In this paper, we present both the theoretical framework and a prototype of a query processing facility that supports the exploration and query of databases from a mobile computer through the manipulation of icons. Icons are particularly suitable for mobile computing since they can be manipulated without typing. The facility requires no special knowledge of the location or the content of the remote database nor understanding of the details of the database schema. Its iconic query language involves no path specification in composing a query. The query facility provides metaquery tools that assist in the formulation of complete queries in an incremental manner on the mobile computer and without involving access to the actual data in the remote database. By not requiring constant access and caching of the actual data, it is able to effectively cope with the inherent limitations in memory and battery life on the mobile computer, disconnections and restricted communication bandwidth, and the high monetary cost of wireless communication.Recommended by: Daniel Barbara, Ravi Jain and Narayanan Krishnakumar  相似文献   

2.
The paper presents a methodology for developing a user interface that combines fourth generation interface tools (SQL forms) with a natural language processor for a database management system. The natural language processor consists of an index, a lexicon and a parser. The index is used to uniquely identify each form in the system through a conceptual representation of its purpose. The form fields specify database or nondatabase fields whose values are either entered by the user (user-defined) or are derived by the form (system-defined) in response to user input. A set of grammar rules are associated with each form. The lexicon consists of all words recognized by the system, their grammatical categories, roots, their associations (if any) with database objects and forms. The parser scans, a natural language query to identify a form in a bottom-up fashion. The information requested in the user query is determined in a top-down manner by parsing, through the grammar rules associated with the identified form. Extragrammatical inputs with limited deviations from the grammar rules are supported. Combining a natural language processor with SQL forms allows processing data modification tasks without violating any database integrity constraint, having duplicate records, or entering invalid data. A prototype natural language interface is described as a front-end to an ORACLE database for a computer integrated manufacturing system  相似文献   

3.
赵猛  陈珂  寿黎但  伍赛  陈刚 《软件学报》2022,33(12):4727-4745
自然语言查询转SQL (NL2SQL)是指将自然语言表达的查询文本自动转化成数据库系统可以理解并执行的结构化查询语言SQL表达式的技术.NL2SQL可以为普通用户提供数据库查询访问的自然交互界面,从而实现基于数据库的自然问答.复杂查询的NL2SQL是当前数据库学术界的研究热点,主流方法采用序列到序列(Seq2seq)的编解码方式对问题进行建模.然而,已有的工作大多基于英文场景,面向中文领域实际应用时,中文特殊的口语化表达导致复杂查询转化困难;此外,现有工作难以正确输出包含复杂计算表达式的查询子句.针对上述问题,提出一种树状模型取代序列表示,将复杂查询自顶向下分解为多叉树,树结点代表SQL的各组成元素,采用深度优先搜索来预测生成SQL语句.在DuSQL中文NL2SQL竞赛的两个官方测试集中,该方法分别取得了第1名和第2名的成绩,验证了其有效性.  相似文献   

4.
After tracing the steps that led to the current generation of iconic languages starting from the original idea of S.K. Chang, we describe an iconic language, named MicroApp, for modeling pervasive mobile applications directly on the mobile device. MicroApp exploits generalized icons for composing mobile applications: services are represented by icons and are composed of adopting colors for representing data-flow. We also qualitatively evaluate the visual environment that implements this iconic language.  相似文献   

5.
In distributed DBMSs, one major issue in developing a horizontal fragmentation technique is what criteria to use to guide the fragmentation. The authors propose to use, in addition to typical user queries, particular knowledge about the data itself. Use of this knowledge allows revision of typical user queries into more precise forms. The revised query expressions produce better estimations of user reference clusters to the database than the original query expressions. The estimated user reference clusters form a basis to partition relations horizontally. In the proposed approach, an ordinary many-sorted language is extended to represent the queries and knowledge compatibly. This knowledge is identified in terms of five axiom schemata. An inference procedure is developed to apply the knowledge to the queries deductively  相似文献   

6.
Zheng  Shihui  Zhou  Aoying  Zhang  Long  Lu  Hongjun 《World Wide Web》2003,6(2):233-253
XML has been recognized as a promising language for data exchange over the Internet. A number of query languages have been proposed for querying XML data. Most of those languages are path-expression based. One difficulty in forming path-expression based queries is that users have to know the structure of XML data against which the queries were issued. In this paper, we describe a DTD-driven visual query interface for XML database systems. With such an interface, a user can easily form path-expression based queries by clicking elements in the DTD tree displayed on the screen and supplying conditions if necessary. The interface and the query generation process are described in detail.  相似文献   

7.
In contrast to a traditional setting where users express queries against the database schema, we assert that the semantics of data can often be understood by viewing the data in the context of the user interface (UI) of the software tool used to enter the data. That is, we believe that users will understand the data in a database by seeing the labels, drop-down menus, tool tips, or other help text that are built into the user interface. Our goal is to allow domain experts with little technical skill to understand and query data. In this paper, we present our GUi As View (Guava) framework and describe how we use forms-based UIs to generate a conceptual model that represents the information in the user interface. We then describe how we generate a query interface from the conceptual model. We characterize the resulting query language using a subset of the relational algebra. Since most application developers want to craft a physical database to meet desired performance needs, we present here a transformation channel that can be configured by instantiating one or more of our transformation operators. The channel, once configured, automatically transforms queries from our query interface into queries that address the underlying physical database and delivers query results that conform to our query interface. In this paper, we define and formalize our database transformation operators. The contributions of this paper are that first, we demonstrate the feasibility of creating a query interface based directly on the user interface and second, we introduce a general purpose database transformation channel that will likely shorten the application development process and increase the quality of the software by automatically generating software artifacts that are often made manually and are prone to errors.  相似文献   

8.
In contrast to a traditional setting where users express queries against the database schema, we assert that the semantics of data can often be understood by viewing the data in the context of the user interface (UI) of the software tool used to enter the data. That is, we believe that users will understand the data in a database by seeing the labels, drop-down menus, tool tips, or other help text that are built into the user interface. Our goal is to allow domain experts with little technical skill to understand and query data. In this paper, we present our GUi As View (Guava) framework and describe how we use forms-based UIs to generate a conceptual model that represents the information in the user interface. We then describe how we generate a query interface from the conceptual model. We characterize the resulting query language using a subset of the relational algebra. Since most application developers want to craft a physical database to meet desired performance needs, we present here a transformation channel that can be configured by instantiating one or more of our transformation operators. The channel, once configured, automatically transforms queries from our query interface into queries that address the underlying physical database and delivers query results that conform to our query interface. In this paper, we define and formalize our database transformation operators. The contributions of this paper are that first, we demonstrate the feasibility of creating a query interface based directly on the user interface and second, we introduce a general purpose database transformation channel that will likely shorten the application development process and increase the quality of the software by automatically generating software artifacts that are often made manually and are prone to errors.  相似文献   

9.
In this paper a visual approach to querying in spatial databases is presented. A filter flow methodology is used to consistently express different types of queries in these systems. Filters are used to represent operations on the database and pictorial icons are used throughout the language for filters, operators and spatial relations. Different granularities of the relations are presented in a hierarchical fashion for spatial constraints. The language framework and functions are described and examples are used to demonstrate its capabilities in representing different levels of queries, including spatial joins and composite spatial joins. Here, the primary focus is on the query language itself but an overview of the implemented interface of the language is also provided.  相似文献   

10.
11.
Kaleidoscope's approach is presented in the context of seeking improvement in the usability of interactive structured query language (SQL) interfaces. The system's cooperation is summarized as proposing valid query constituents step-by-step and providing lexical and semantic feedback immediately to users. To implement this intraquery guidance, the context-free grammar (CFG) is extended to capture the constraints useful for intraquery guidance, and the knowledge useful for pruning nonsensical queries and providing semantic feedback is articulated. For the SQL interface, this knowledge includes a strong domain concept, functional dependency, and integrity constraint rules, which can be acquired once in the database design step. The same types of knowledge are useful both for postquery cooperation and intraquery guidance. As SQL is supported bv virtually all database management system (DBMS) vendors, the approach presents a practical solution for casual database access  相似文献   

12.
This paper presents a visual query language called VQL for interacting with an object-oriented schema-intensive data model. VQL allows convenient access to the various types of knowledge captured by the semantic model. It consists of a set of “graphical primitives” along with a combination grammar for creating graphical queries. The visual language is internally supported by a prolog-like predicate based query language. The formal grammar underlying the predicate based language is also presented. Apart from being able to create simple queries that can be specified in SQL or QBE, VQL can be used for making queries on any object-oriented data model including the generalization of the E-R model. VQL also handles complicated, indirect queries, specially those that require a reasoning system for query interpretation and response generation. Further, recursive queries on graph structures such as finding transitive closures of graphs may be easily specified. Perhaps the most powerful feature of VQL is its ability to provide high semantic expressibility (in being able to specify highly complex queries) while maintaining simplicity in the user's query formulation process. VQL is embedded in an object-oriented graphical database interaction environment that supports schema creation and manipulation in addition to database querying and updation. The prototype has been implemented in Smalltalk-80 running on a Sun 3/60 workstation. All the illustrations of visual interaction presented are taken from actual interaction sessions  相似文献   

13.
We define the query language Vizla, in which answers to queries are built up by pointing to representations of sets and functions in a conceptual model of the data base of an application, and to iconic identifiers of computational operators or control constructs. At its present stage of development the primary use of Vizla is in the validation of conceptual models of information systems, but it is to be developed into a user interface to SF, a prototyping language for information and control systems. Moreover, it can be regarded as a visual programming language in its own right. As such it is based on abstract data types  相似文献   

14.
Online information repositories commonly provide keyword search facilities through textual query languages based on Boolean logic. However, there is evidence to suggest that the syntactic demands of such languages can lead to user errors and adversely affect the time that it takes users to form queries. Users also face difficulties because of the conflict in semantics between AND and OR when used in Boolean logic and English language. Analysis of usage logs for the New Zealand Digital Library (NZDL) show that few Boolean queries contain more than three terms, use of the intersection operator dominates and that query refinement is common. We suggest that graphical query languages, in particular Venn-like diagrams, can alleviate the problems that users experience when forming Boolean expressions with textual languages. A study of the utility of Venn diagrams for query specification indicates that with little or no training users can interpret and form Venn-like diagrams in a consistent manner which accurately correspond to Boolean expressions. We describe VQuery, a Venn-diagram based user interface to the New Zealand Digital Library (NZDL). In a study which compared VQuery with a standard textual Boolean interface, users took significantly longer to form queries and produced more erroneous queries when using VQuery. We discuss the implications of these results and suggest directions for future work. Received: 15 December 1997 / Revised: June 1999  相似文献   

15.
A system to query databases using diagrams as a standard user interface is proposed. The system, called Query by Diagram* (QBD*), makes use of a conceptual data model, a query language on this model, and a graphical user interface. The conceptual model is the entity-relationship model. The query language, whose expressive power allows recursive queries, supports visual interaction. The main characteristics of the interface are ease of use and the availability of a rich set of primitives for schema selection and query formulation. The expressive power of QBD* and G+, which are the only languages allowing recursive queries to be expressed graphically are compared  相似文献   

16.
In recent years, the availability of complex data repositories (e.g., multimedia, genomic, semistructured databases) has paved the way to new potentials as to data querying. In this scenario, similarity and fuzzy techniques have proven to be successful principles for effective data retrieval. However, most proposals are domain specific and lack of a general and integrated approach to deal with generalized complex queries, i.e., queries where multiple conditions are expressed, possibly on complex as well as on traditional data. To overcome such limitations, much work has been devoted to the development of middleware systems to support query processing on multiple repositories. On a similar line, We present a formal framework to permeate complex similarity and fuzzy queries within a relational database system. As an example, we focus on multimedia data, which is represented in an integrated view with common database data. We have designed an application layer that relies on an algebraic query language, extended with MM-tailored operators, and that maps complex similarity and fuzzy queries to standard SQL statements that can be processed by a relational database system, exploiting standard facilities of modern extensible RDBMS. To show the applicability of our proposal, we implemented a prototype that provides the user with rich query capabilities, ranging from traditional database queries to complex queries gathering a mixture of Boolean, similarity, and fuzzy predicates on the data.  相似文献   

17.
John H. M. De Vet 《Software》1989,19(5):491-504
This paper describes an algorithm for evaluating database queries represented as expressions in a logical language. Such a database query expression can be evaluated efficiently by focusing on the variable dependencies. The algorithm recursively computes the values of subexpressions to evaluate the input expression, but it avoids re-evaluation of those subexpressions whose values are not affected by new variable assignments. The input expression is internally structured as a directed acyclic graph. Two additional techniques to improve efficiency of the evaluation are discussed: transformations of the input expression and special primitive database operations. Finally, its implementation in the natural language question-answering system SPICOS is described.  相似文献   

18.
PICASSO (PICture Aided Sophisticated Sketch Of database queries) is a graphics-based database query language designed for use with a universal relation database system. The primary objective of PICASSO is ease of use. Graphics are used to provide a simple method of expressing queries and to provide visual feedback to the user about the system's interpretation of the query. Inexperienced users can use the graphical feedback to aid them in formulating queries whereas experienced users can ignore the feedback. Inexperienced users can pose queries without knowing the details of underlying database schema and without learning the formal syntax of SQL-like query language. This paper presents the syntax of PICASSO queries and compares PICASSO queries with similar queries in standard relational query languages. Comparisons are also made with System/U, a non-graphical universal relation system on which PICASSO is based. The hypergraph semantics of the universal relation are used as the foundation for PICASSO and their integration with a graphical workstation enhances the usability of database systems.  相似文献   

19.
IBS (Icon Based System) is an experimental graphical query language based on icons. It demonstrates the capabilities of a workstation environment by integrating the aspects of database programming in one graphical setting. Namely, it allows direct manipulation of objects dealing with pictorial data as well as alphanumeric data. We point out the interaction techniques between users and database systems. Then we describe the design of IBS, illustrate its features, and show how queries are formulated in a medical context.  相似文献   

20.
基于Ontology的数据库自然语言查询接口的研究   总被引:3,自引:1,他引:2  
提出了一种基于Ontology的关系数据库自然语言查询接口的系统模型及设计框架.采用WordNet作为基本数据库并在WordNet之上定义领域词库,可以提高语法分析的识别率;同时利用Ontlogly知识表达能力存储关系数据库概念模型,并对概论模型的内容进行扩充;另外对Ontology和WordNet的同义词集进行关联,可以提高语义的识别率.用户的输入查询语句通过语法分析、语义分析生成中间表达式语言DRS,然后通过模板技术转换成SQL,通过DBMS执行SQL并返回结果.实验证明,这种方案不但实用可行,而且通过逐步完善Ontology知识库的定义,可以大大提高查询的命中率;另外通过WordNet和Ontology定义领域词库和领域知识,提高了系统的可移植性.最后,所提供的方法可以很容易地移植到其他领域.  相似文献   

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